Perhaps you should try some spelling variations:
present challenges » current challenges, assessment challenges
wang liang » wang yang
min hyoung » min hong, mun young
a present » _ present, 3 present, 2 present
m hyoung » _ young, a young, 3 young
yang yi » yang di, yang xi, yang jui
ng y » ng _, g y, na y
y a » y la

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang liang) OR (yang yi))ng y a present challenges ((m hyoung) OR (min hyoung)) hai ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang liang) or (yang yi))ng y a present challenges ((m hyoung) OR (min hyoung)) hai ;~".
• Adding a wildcard symbol may retrieve word variants: ((wang liang) or (yang yi))ng y a present challenges ((m hyoung) OR (min hyoung)) hai ;*.